Field of the Invention
The invention relates to a nuclear power station having a gas-injection device intended for a coolant.
A feedwater/steam circuit is normally provided in a nuclear power station. The feedwater/steam circuit can serve as a cooling circuit for cooling a reactor core. In that case, a coolant provided in the cooling circuit depends on the type of reactor and can be water, in particular in a pressurized-water reactor or boiling-water reactor.
Provision is normally made for the introduction of hydrogen into the coolant in order to counter a radiolytic decomposition of the coolant flowing in the feedwater/steam circuit. For that purpose, a volume-control system for a pressurized-water reactor has been disclosed, for example, by a book entitled “VGB-Kernkraftwerks-Seminar 1970” [VGB Nuclear Power Seminar 1970], in particular on page 41. That volume-control system is suitable for feeding chemicals, in particular hydrogen, into the feedwater/steam circuit of the nuclear reactor.
In the known system, the hydrogen is fed into a volume—compensating tank belonging to the volume-control system. The hydrogen fed in to the volume-compensating tank is present as a constituent of a gas cushion above a liquid level of the coolant. In that case, the hydrogen partial pressure in the gas cushion is set in accordance with the desired concentration of the hydrogen in the cooling medium.
A further development of the system described above has been disclosed by German Published, Non-Prosecuted Patent Application DE 196 02 213 A1, corresponding to U.S. application Ser. No. 09/050,651, filed Mar. 30, 1998. In the feed system described in that publication, the hydrogen is introduced into the coolant by a hydrogen generator disposed in the feedwater/steam circuit. In that case, the hydrogen generator is an electrolytic device, as disclosed, for example, in a book entitled “Die Grundlagen der Ingenieurwissenschaften” [The Fundamentals of the Engineering Sciences] by Hutte, Springer (1996), pages B167 and the following.
Furthermore, German Patent DE 195 36 450 C1 discloses a nuclear reactor, during the operation of which hydrogen is added to the coolant. In that case, the addition of hydrogen depends on the hydrogen content of the coolant, which is continuously measured through the use of a measuring device on the pressure side of a high-pressure pump.
However, those systems have considerable maintenance and repair costs. In addition, there are certain locations in the feedwater/steam circuit which have an increased concentration of the hydrogen, since a sufficient distribution of the hydrogen in the coolant is not ensured.